dingusppc/devices/storage/blockstoragedevice.cpp
joevt 3978d0754d CD-ROM: Add max blocks check.
The code does not support more than 2^32 - 2 blocks because of this expression: static_cast<uint32_t>(this->size_blocks + 1)
2024-03-01 08:01:31 -07:00

107 lines
2.9 KiB
C++

/*
DingusPPC - The Experimental PowerPC Macintosh emulator
Copyright (C) 2018-23 divingkatae and maximum
(theweirdo) spatium
(Contact divingkatae#1017 or powermax#2286 on Discord for more info)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
/** @file Block storage device implementation. */
#include <devices/storage/blockstoragedevice.h>
using namespace std;
BlockStorageDevice::BlockStorageDevice(const uint32_t cache_blocks, const uint32_t block_size, const uint64_t max_blocks) {
this->block_size = block_size;
this->cache_size = cache_blocks * this->block_size;
this->max_blocks = max_blocks;
// allocate device cache and fill it with zeroes
this->data_cache = std::unique_ptr<char[]>(new char[this->cache_size] ());
}
BlockStorageDevice::~BlockStorageDevice() {
this->img_file.close();
}
int BlockStorageDevice::set_host_file(std::string file_path) {
this->is_ready = false;
if (!this->img_file.open(file_path)) {
return -1;
}
this->size_bytes = this->img_file.size();
this->size_blocks = this->size_bytes / this->block_size;
if (this->size_blocks > this->max_blocks)
return -1;
this->set_fpos(0);
this->is_ready = true;
return 0;
}
int BlockStorageDevice::set_fpos(const uint32_t lba) {
this->cur_fpos = lba * this->block_size;
return 0;
}
int BlockStorageDevice::read_begin(int nblocks, uint32_t max_len) {
uint32_t xfer_len = std::min(this->cache_size, max_len);
uint32_t read_size = nblocks * this->block_size;
if (read_size > xfer_len) {
this->remain_size = read_size - xfer_len;
read_size = xfer_len;
} else {
this->remain_size = 0;
}
this->img_file.read(this->data_cache.get(), this->cur_fpos, read_size);
this->cur_fpos += read_size;
return read_size;
}
int BlockStorageDevice::read_more() {
uint32_t read_size;
if (!this->remain_size)
return 0;
if (this->remain_size > this->cache_size) {
this->remain_size -= this->cache_size;
read_size = this->cache_size;
} else {
read_size = this->remain_size;
this->remain_size = 0;
}
this->img_file.read(this->data_cache.get(), this->cur_fpos, read_size);
this->cur_fpos += read_size;
return read_size;
}
int BlockStorageDevice::write_begin(char *buf, int nblocks) {
if (!this->is_writeable)
return -1;
return 0;
}